1. Field of the Invention
The present invention relates to valve locking devices and, more particularly, to a locking bracket for a valve actuator.
2. Description of the Related Art
It is common for pipeline valves to be constructed with an operating mechanism in which an input shaft must be rotated in order to open, close, or adjust the valve. A typical example is a pipeline flow control valve having a handwheel affixed to the input shaft of a valve actuator. To adjust the rate of fluid flow, the handwheel is rotated, thus also rotating the input shaft and causing the actuator mechanism of the valve to operate.
It is frequently desirable to provide a means for locking the operating mechanism of a valve so that the setting of the valve may not be easily disturbed, whether through mistake, inadvertence, or mischief. To this end, devices are available for attachment to a valve actuator that will lock the actuator and prevent or deter operation of the valve.
Heretofore, valve locking devices have necessitated the disassembly and reassembly of several components of the valve or the valve actuator. For example, a locking device is known in which the valve actuator from which the input shaft extends must be unbolted, a bracket is placed over the shaft, and the bracket is affixed to the actuator by replacing the bolt or bolts which were removed. The bracket and the handwheel each have a welded flange concentric with the drive shaft. The flanges have openings which are aligned with each other. A pin, bolt, or shackle is inserted through an aligned pair of openings of the two flanges.
Valve locking devices of the past have been subject to disadvantages in terms of the time, expense, and special skills required to affix the device to the valve. Accordingly, there is a heretofore unmet need for a valve locking device that is easily installed, requiring a minimum of disassembly and reassembly.